Method of preserving eggs and products



. UNITED STATES PATENT OFFICE METHOD OF -PRESERVING EGGS AND PRODUCTS Arthur V. Swarthout, San Francisco, and Miroslav Tamele, akland, Calih, assignors to ,Ovolo Incorporated, Oakland, Calif., a corporation of California No Drawing. Application April 10, 1934,

- Serial No. 119,892

16 Claims. (Cl. 99-113) The present invention relates to the substantial ethers, esters and mixed ether-esters, molasses,

destruction of microorganisms in eggs and/or honey, and other equivalent syrups, ethyl alcohol,

the substantial inhibition of bacteria growth tartaric acid, lactic acid, malic acid, and the and/or the preservation of eggs for commercial water-soluble salts thereof, the alkylolamines etc.

purposes and to the products resulting therefrom. A sufficient quantity of the hydroxylated com- 5 More particularly it is concerned with the paspound or its derivative is incorporated with the teurization in vacuo or under a partial pressure egg mass to produce a substantially homogeneous of oxygen substantially less than one-fifth of. an liquid mass when the mixture is heated from atmosphere of egg contents whereby the mateabout a moderately elevated temperature to one 10 rials are preserved or guarded against spoilage slightly above the normal coagulation tempera- 10 for indefinite periods, budding yeasts killed and ture of the untreated eggv mass, i. e. from about the activity of molds obviated. 100 to about 145? at atmospheric pressure. The process is adapted for the treatment of When employing polyhydrlc alcohols of the nawhole eggs removed from their shells, of mixtures ture of carbohydrates such as the sugars, we prefof whites and yolks combined in diiferent'proporerably utilize from about 40 to 60% by weight 15 tions, of yolks alone and of egg whites alone, alof the same while homogenizing at a temperature though in those cases where treatment with an in the neighborhood of 145 F. This operation is edible, neutral salt system is included, the step effective y executed o a water-ba h althou h of treating whites per se may be excluded. other suitable heating means may be resorted to.

Numerous methods have been proposed for pre- As a result of this treatment, the mixture under- 20 serving eggs intheir natural wholesome condigoes several fundamental changes. It forms a tion and without objectionable flavor and odor. homogeneous, liquid egg product whose coagulasome of the best known of these methods are tion temperature, in many cases, especially where freezing, desiccating, dehydrating or ageing. As carbohydratesas sugars have been utilized,'is customarily practiced by others, the mere freezabove that of untreated albumin, which product mg, drying, evaporating or ageing processes inis already in a substantially preserved state in a evitably fail to prevent decompositionand/or fermajority of instances. Where sugars are emmentation of the eggs and the accompanying wellployed, particularly the diand tri-sacchafldes, known objectionable odor and flavor. inversion thereof takes place. The inversion is Our. present invention relates to the preservausually directly proportional to the total length 80 tion and/or pasteurization and the like of broken of heat treatment. It is, for bakers, a highly dewhole eggs; egg yolks, any admixture of egg yolks sirable characteristic as levulose apparently preand whites, and whites so that they may be kept serves the moisture in baked products. The osin liquid form without deterioration or'impalrmotic pressure is increased considerably with the ment for indefinite periods. It also comprises the inversion of sugars and is apparently a main facpreparation ofpreserved, partially dehydrated egg tor in the prevention of bacteria growth. They contents andthe manufacture of egg preparaaddition of invertase is helpful in certain cases, tions of syrup-like consistency and the like. as for example, with beet sugar. The mem- Our invention may- -be practiced in the followbranes, germs, strings or chalazae are substaning manner. The egg contents are intimately tially completely dissolved or disintegratedincer- 40 incorporated or thoroughly mixed via agitation, tain cases, thus obviating the necessity for straincentrifuging or in any suitable manner known to ing with the consequent loss of egg contents. the art with an effective amount of an hydroxylstraining may be resorted to when, due to negliated, edible, water-soluble carbon compound, gence in temperaturecontrol, addition of certain whose hydroxy group or groups may be esterifled agents, etc., slight coagulation may ensue or-when and/or etherified, adapted to function as a prean hydroxylated. compound is employed which servative and/or as an emulsion stabilizer and/or does not function to materially dissolve, or disas a solubilizing medium and/or as an agent eifecintegrate the fibrous materials. The intimately tive in raising the coagulating temperature of the incorporated hydroxylated compound or derivaegg mass substantially above that of the untreated tive completely permeates the entire disintegrated egg mass. Among the numerous compounds cellular structure of the egg contents thus obviatavailable may be enumerated the polyhydric alcoing local decomposition and thereby retaining the hols as the glycols, the polyglycols, glycerol, the viscosity and beating and other desirable proper- 5 carbohydrates including the sugars known as the ties of'the egg product. When incorporated in monoses, disaccharides and polysaccharides, their baked products, the latter may bekep't moist by the selection of appropriate hydroxylated compounds of suitable hygroscopicity. Not only is the egg viscosity increased in certain instances but, as a general rule, the proteinaceous,colloldal particles are prevented from agglomerating.

In executing the homogenizing step, it is desirable to avoid beating or foam formation as otherwise air is entrained or entrapped in the e product thereby impairing the preservative effect of the various operations. Consequently, where mixers are resorted to, they should, desirably, be substantially completely submerged in the admixed egg product containing one or more of the hydroxylated compounds.

The resulting admixed egg product then is cooled by suitable cooling means to about room temperature or slightly higher, i. e., from about 70 to F., at atmospheric pressure. This cooling stage is-essential and preparatory to the incorporation of one or more edible, water-soluble neutral salts such as sodium chloride, sodium acetate, sodium phosphate, sodium citrate, sodium tartrate, sodium lactate, sodium malate, sodium of the egg product. The original opaque, goldenyellow-colored mixture of honey-like consistency is clarified especially in the additional presence of a sugar, its opacity is removed and its consistency changed to a syrup-like liquid, 1. e., its viscosity is slightly lowered. The color, also, is considerably darkened and the flavor is improved. The resulting product is a. bright, clear, syrup-like liquid of amber color, greatly improved for cake baking and the like.

It is desirablethat the neutral salt or clarifying agent and controller of viscosity be added within the proper temperature range as the clarifying action is seriously retarded at those temperatures at which there is a relatively slow rate of solution of the neutral salt system in the admixed egg product. On the other hand, too elevated temperatures prevent the neutral salt system from functioning as a clarifying agent as well as impair the control of viscosity of the egg product. at the proper temperatures, the clarto be added is quite small, varying from about 0.2 to 2% by weight although we have found quantities of from about 0.5 to 1% quite satisfactory. The exact quantity to be added will depend on the desired viscosity of the end-product and on the desired shade of color of the same.

Upon completion of the clarifying and viscosity control step which ordinarily requires about 15 minutes per 200 pounds of yolks and whites and about 12 minutes per pounds of yolks and whites containing about 50% by weight of sugar, the liquid egg composition may be permitted to ripen or age for any desirable period, say from about 6 to 36 hours. This procedure is believed to accomplish the proteolytic decomposition of proteins and enhance the leavening powers of the final product.

At the completion of this ripening period, or after the clarifying stage when ripening is not resorted to. the intermediate product may be sealed hot, warm or cold (room temperature) in containers. preferably under a high vacuum. By

sealing under sub-atmospheric pressures, air and other occluded deleterious gases are expelled substantially completely from the egg product thus further insuring the keeping qualities of the finished egg product. The degree of vacuum may vary but should be preferably as nearly absolute as possible without causing the containers to collapse.

Mold spore activity can be decreased by replacing air with nitrogen, CO: and/or other inert gases, the sealed product being then accorded a treatment or treatments corresponding to those given to egg contents sealed in vacuo.

The hot treatmentcomprises sealing while the egg product is at a moderately elevated temperature, say from about to 160 F., and may be utilized to produce the existing low pressure in the containers. The filled containers, as soon as they have been sealed, are cooled, preferably under water. The purpose of this step is to fairly rapidly cool the entire contents of the containers; otherwise the material in the center of the container remains warm for a relatively long period thus favoring coagulation of part of the egg product.

Whether the egg product is sealed cold, warm or hot, after it has been sealed and is approximately at room temperature or say 80 F., it may be permitted to ripen or age for a suitable period for the purpose previously described. Whether or not the sealed product is permitted to undergo ripening, it is subjected to one or more successively spaced heat treatments whereby pasteurization of the end-product is substantially effected. A suitable temperature range is from to 170 F., the period of treatment sufficient to effect substantial microorganism destruction varying with the bulk. the temperature, the degree of vacuum and the composition of the egg product. Heating to about F., from about onehalf to one and one-fourth hours usually sumces for each heating. .With 8 pounds of egg products/#10 tins, one hour is usually sufficient. The pasteurization of the product is essential in order to destroy or inhibit the growth of the sugartolerant yeasts which may be present and which favor bacteriological decomposition and/or paralyze or inhibit the growth of bacteria.

The products then are cooled quickly to not higher than 85 F., preferably between 70 to 80 F., in order to prevent coagulation occurring through the relatively slow dissipation of heat. If desired, the heat or pasteurization treatment followed by relatively rapid cooling may be repeated one or more times preferably executed at least twice, thus completely insuring the inhibition of any bacterial activity. It is desirable to reheat the product after a period of ripening of about twenty hours or more has elapsed. When the method thus described is carefully carriedout, the resulting product has a .color,

. flavor and mobility highly desirable in the culistrained prior to admixture with hydroxylated carbon compounds, which straining operation may or may not be preceded by an ageing or ripening period. Alternatively, after admixture of the egg contents and hydroxylated carbon compound, the mixture may be strained before being subjected to the first heat treatment.

Still another modification may be practiced by other hand, the invention is to be aoeavae subjecting an admixture of egg contents and bydromlated carbon compound, with or without incorporation of -a neutral, edible, water-soluble salt system, to packaging invacuo while hot or cold without apreceding heat treatment and subsequently subjecting the sealed product to one or more heat or pasteurization treatments followed by relatively rapid cooling operations. The

air-in the container may have been displaced by an inert gas in lieu of packaging in vacuo.

Where partially or moderately dehydrated products are desired, the first heat treatment may be carried at higher temperatures or for longer periods or may be supplemented, by blowing inert gases through the liquid mass or by execution at subatmospheric pressures. The quantity of water to beremoyed will control the character or the-treatment, the time of execution, and will I result in greater thermal stability of the product.

The expressions eggcontents and egg mea as used throughout the specification aiid claims, are intended to embrace broken whole eggs, yolks and whites of eggs in varying proportions, andlyolks or whites alone, whether with their original water-content or less.

while we have in the foregoing described in some detail the preferred embodiment of our .invention and some variants thereof, it will be understood that this is only .for the purpose oi making the invention more clear and that the invention is not to be regarded as limited to the details of operation described,"nor is it dependent upon the soundness or accuracy of the theoris which we have advanced as to the reasons for the advantageous results attained. 0n the regarded as limited only by the'terms oi the accompanying claims, in which it is our intention to claim-all novelty ,inherent therein as broadly as is' possible in view of the prior art.

We claim as our invention:

1 The method of preserving egg contents which comprises subjecting a mixture of egg meat and a preservative quantity of an edible, water-soluble compound 01' the class consisting of hydroxylated carbon compounds, their 'ethers,"esters and f salts in a sealed receptacle to apasteurization temperature at which substantial destruction of micro-organisms is effected and for a time at which substantial coagulation of albumen is avoided, relatively rapidly dissipating the heat from the sealed product, allowing the product to age for a suitable period and repeating the heating and cooling treatments at least once again.

2. 'The method of preserving egg contents which comprises subjecting a mixture of egg meat and a preservative quantity "of sugar in a sealed re,- ceptacle to a temperature at which substantial destruction of micro-organisms is eiiected and for a time at which substantial coagulation of albumen-is avoided, relatively rapidly dissipating the (heat from the sealed product, allowing the product to age for a suitable period and repeating the heating and cooling treatments at least once again to ensure the substantial inhibition of any bacterial activity.

3. The method of preserving egg contents which it comprises heating the same with a quantity of 7 substantial coagulation of albumen,

sugar suiiicient to produce a smooth flowing homogeneous liquid mass while avoiding substahtial coagulation of albumen,-separating membranous material from said mass, sealing said mass in'a receptacle, heating the sealed product to a pasteurization temperature while avoidin relatively product.

rapidly cooling the sealed product; allowing the sealed product to age for at least six hours and repeating the least once again. V

4. The method oi preserving egg contents which comprises heating a mixture oi e meat and sugar containing between'40 and] 60%, by weight, ofsugar in a sealed receptacle to from heatin and cooling treatments at about 155 to 170 F; iofatime at which substantial coagulation of albumen 'is avoided,

tively rapidly cooling the product to below about F., allowing the product'to age for at least several hours and repeating the heating and cooling treatments at least once again to ensure the substantial inhibition of any bacterial activity.

relav5. The method ofpreseryingl egg contents which comprises heating egg meat with a pre-. servative quantit of sugar to a pasteurizing'temperature wherea a substantially homogeneous liquid mass is attained'while avoiding the substantial coagulation of albumen; cooling .the mixture to about 70 to F., adding a quantity of a water-soluble, edible, neutral salt 'sufllcient to clarify the mixture, sealing the mixture in a re ceptacle, pasteurizingthe mixture while avoiding substantial coagulation of albumen and relatively rapidly dissipating the heat from the sealed 6. The method of preserving egg contents which comprises mixing egg meat'with such a quantity of sugar at an elevated temperature whereat a substantially homogeneousliquid mass containing about '40 to 60%, by weight, of sugar is attained while avoiding the substantial coagulation of albumen, cooling the mixture to about 70 to 90 F.-, adding from about 0.2 to 2%, by weight, of sodium chloride, sealing the mixture in a receptacle, pasteu'rizing the mixture while avoiding substantial coagulation of albumen and 1 relatively rapidly dissipating the heat from the I sealed product.

7. The method' of preserving egg contents which comprises subjecting egg meat mixed with. a preservative quantity of sugar and a clarifying quantity of sodium chloride while sealed in a container to a pasteurlzing treatment while avoiding substantial coagulation of albumen, relatively rapidly dissipating the heat from the sealed product, allowing the product to agefor a. suitable period and repeating the heating and cooling treatments at least once again to ensure the substantial inhibitionof any bacterial activity.

8. The method of preserving egg contents which comprises heating egg meat with a preservative quantity of sugar to about F. for

time sufficient to form a homogeneous product, permitting the mixture to cool to about 70 to 90 F.,' subjecting the at least six hours, sealing the mixture in a receptacle, pasteurizing the mixture while avoiding substantial coagulation of "albumen and relatively rapidly dissipating the heat from the sealed prod- -uct at the end of the pasteurization treatment.

- 9. The method of preserving egg contents which comprises heating a mixture of egg meat andsugar containing about 40 to 60% by weight,

of sugar to about 145 F. form a homogeneous product, permitting the mixture to cool to about '70 to 90 F.,' adding a quan-- tity of a water-soluble, edible, neutral salt sufilcient to'cl'arify the mixture, subjecting the mixmixture to an ageing period of,

for a time suiilcient to v ture to an ageing period of at least six hours,

relatively rapidly dissipating the heat from the 'which comprises heating eggmeat with a preservative quantity oi an edible, water-soluble compoundio'f the class consisting of hydroxylated their ethers, esters and salts carbon compounds, to a pasteurization temperature while avoiding the substantial coagulation of albumen. sealing the mixture in a receptacle and pasteurizing the sealed mixture while avoiding the substantial coagulation of albumen.

11. The method of preserving egg contents which comprises heating egg meat with a preservative quantity of sugar to apasteurization temperature while avoiding the substantial coagulation of albumen, cooling the mixture, sealing said mixture in a receptacle, pasteurizing the sealed mixture while avoiding the substantial coagulation of albumen and relatively rapidly dissipating the heat from the sealed product. 12. A preserved, clear, heat-treated egg product of substantially inhibited bacterial activity, which is relatively stable under atmospheric conditions and which contains a preservative quantity of sugar and a clarifying quantity of sodium chloride.

' is relatively stable under atmospheric conditionsducing, agent.

13. A preserved, clear, heat-treated egg product of substantially inhibited bacterial activity, which and which contains about 40 to by weight, 01' sugar and about 0.2 to 2% sodium chloride.

14. A preserved, clear, heat-treated egg product of substantially inhibited bacterial activity, which is relatively stable under atmospheric conditions and which contains about 40 to 60%, by weight, of sugar and aclarifying quantity of sodium chloride.

15. A preserved, clear, heat-treated egg product of-substantially inhibited bacterial activity, which is relatively stable 'under atmospheric conditions and which contains a preservative quantity of an edible, water-soluble compound of the class consisting of hydroxylated carbon compounds, their ethers, esters and salts and a clarifying quantity of sodium chloride.

16. A preserved, clear, heat-treated egg product 01' substantially inhibited bacterial activity, which is relatively stable under atmospheric conditions and which contains a preservative quantity of sugar and a clarifying quantity of a water-soluble, edible, neutral, inorganic salt which is not. a re- .m'mmz v. swanrnour. MIROBLAV TAMELE. 

